Dynamic load compensating valve



May 3, 1966 J. ALBERANI ETAL 3,249,145

DYNAMIC LOAD COMPENSATING VALVE Filed April s, 1964 /a/E y Jal /I/ALERA/V/ R/VALD JT 6A VASE INVENTORS ATTORNEY United vStates Patent()3,249,145 DYNAMIC LOAD COMPENSATING VALVE Julius Alberani, Warren, andRonald J. Savage, Birmingham, Mich., assignors to Holley CarburetorCompany, Warren, Mich., a corporation of Michigan Filed Apr. 3, 1964,Ser. No. 357,150 1 Claim. (Cl. 15S-36.5)

This invention relates generally to combined flow and pressureregulators, and more particularly to a valve for eliminating the effectof dynamic or G loading on lluel flowing through a moving conduit.

In certain gas turbine engine applications, such as ground-to-airmissiles, the engine is started and brought up to maximum speed on theground by the use of auxiliary equipment that s disconnected before themissile is launched. The missile fuel system may be very simple, ascompared to the auxiliary equipment; for example, it may comprise merelya pressurized fuel tank mounted near the front of the engine and aninexpensive, slow reacting, pressure responsive governor located justupstream of the nozzle that discharges fuel into the engine burnerchamber which is at ambient pressure. While it is desired to maintainthe fuel flow to the engine constant once the missile is launched, themissile is accelerated throughout its mission and any G loading in fuellines parallel to the direction of flight causes an excessive fuelsupply that may cause the engine to overspeed or overheat.

Accordingly, it is a primary object of the invention to provide a v-alvewhich may be inserted inthe conduit communicating between the source offuel and the discharge nozzles which automatically eliminates the Gloading effect on the fuel wihch is flowing through the conduit.

A further object of the invention is to provide such a valve whichmaintains both the fuel flow and the pressure immediately upstream ofthe nozzles constant.

Still another object of the invention is to provide such a valve `whichis compact and light-weight, efficient and reliable, and inexpensive andeasy to manufacture.

A still further object of the invention is to provide such a valve andassociated resilient means having provisions for cancelling out theeffect of increased spring force on the valve resulting from compressionof the resilient means.

Other more specific objects and advantages of the invention will becomemore apparent when reference is made to the following specification andthe accompanying drawings wherein:

'FIGURE l is a schematic illustration of a gas turbine engine fuelsystem having a G load compensator valve embodying the invention;

FIGURE 2 is an enlarged cross-sectional view of the G load compensatorvalve shown in FIGURE 1; and,

FIGURE 3 is a schematic illustration of the valve shown by FIGUR-E 2.

Referring now to the figures in greater detail, FIGURE 1 illustrates agas turbine engine 10 having a source of fuel including a pressurizedfuel tank 12 and a tank pressure Iregulator valve 14, for controllingthe pressure of air supplied |by the engine. Conduits 16 and 18communicate between the pressurized fuel tank 12 and the fuel dischargenozzles 13 located in the engine 10, and the G loading compensator valve20 is inserted in series in the fuel feed line Amade up of conduits 1'6and 18.

As illustrated in FIGURE 2, the compensator valve 20 may comprise atwo-piece housing 22 having an inlet 24 and an outlet 26 suitablyconnected to conduits 16 and 1.8, respectively, of :FIGURE 1. Apassageway 28 communicates between the inlet 24 and a chamber 30, andanother chamber 32 communicates with the outlet 26. An opening 34provides communication between charnbers 30 and 32.

Patented May 3, 1966 ICC The housing 22 further includes chambers 36 and38 and a diaphragm 40 forming a movable wall therebetween. A valveassembly 42, having a suitably contoured end 44 co-operating with theopening 34 and a flanged end 46 adjacent the diaphragm 40, is slidablymounted in an opening 48 between the chambers 30 and 36, the latterhaving a forward wall 47. A passageway 50 communicates between thechamber 32 and the chamber 36. Should the valve 44 |be found to reacttoo quickly, a plug 49 having a calibrated restriction 51 may beinserted in the passageway 50.

A spring seat 52 is secured to an extension 54 of the flanged end 46through a center opening 56 in the diaphragm 40 in a manner to confinethe center of the diaphragm 40 between spring seat 52 and the flangedend 46, the pe-riphery of the diaphragm being clamped .between the cover53 and a ring 55. A spring 58 is confined at its one end by a wall ofthe chamber 3'8 and at its other end by the spring seat 52. Anadjustable stop 59 may be located in the chamber 38 in order to preventthe valve 44 from ever closing completely for any reason.

An outlet passageway 60 communicates between the chamber 38 and theatmosphere surrounding the two-piece housing 22. In the event thehousing 22 is mounted in an unsuitable atmosphere, such as in a chamberof the gas turbine engine 10 which is affected by ram pressure, externalthreads 62 may -be provided to receive a tting and a conduit (not shown)leading to a suitable external atmosphere. If desired, the housing 22may include suitable mounting lugs 64.

Operation,

The operation of the dynamic load fuel compensator 20 can lbest beexplained by referring to the schematic illustration of FIGURE 3. If amissile powered by the gas turbine engine 10 were standing still ormoving at a constant speed, the valve 44 would remain fully open becausethe force of the spring 58 against the spring seat 52 is sufllcient tohold the flange 46 against the forward wall 47 of the chamber 36. Inthis state, pressure P4 at the upstream side of the discharge nozzle 13would be the same as the regulated pressure P1 of the .fuel as it leavesthe pressurized fuel tank 12, if line loss is neglected.

If no valve 44 is present and the missile is accelerating, the G loadingeffect on the fuel flowing through the relatively long conduit 116 andthence through the conduit 18 will cause pressure P4 to increase. Aspreviously mentioned, the engine pressure downstream of the nozzle 13remains at ambient pressure Pa; hence, an increased pressure drop P4-Pawould exist across the nozzle 13. This increased pressure differentialwould cause an increased fuel flow through the nozzle 13, resulting inthe engine overspeeding or overheating.

The above vdescribed excessive pressure and flow caused by the effec-tof acceleration is eliminated by the use of the dynamic load fuelcompensator 20 between the conduits 16 and 18, the direction of flightin FIGURES 1-3 being from right to left. P2 designates the increasedpressure at the inlet passageway 28 which results from the G loading onthe fuel flowing through that portion of conduit 16 that is parallelwith the direction of flight. When P2 increases due to acceleration,pressure yP3 in the chamber 32 and pressure P5 in the chamber 36 willalso increase. This causes the diaphragm 40 and everything connectedthereto, including valve 44, to move to the right in FIGURE 3 againstthe forces of the spring 58 and the ambient pressure Pa in the chamber3-8 on the diaphragm. The result is a decrease in the flow area betweenthe opening 34 and the valve 44. Consequently, pressure P3 in thechamber 32 will be reduced, as will pressure yP5 in the chamber 36. Thereduction in these pressures will continue until the force due to thepressure differential, P-Pa, across the diaphragm 40 equals the force ofthe compressed spring 58, at which time the pressure P4 and fuelowthrough the nozzle will be free of the eifect of.G loading.

The various design factors of the valve assembly shown by FIGURE 2,such` as the initial force and rate of the spring 58, fthe areaof thediaphragm 40, the size of the opening 34, the contour and travel of thevalve 44 and the direction of flight lengths L1, L2 and L3 (see FIGURE3), are critical for any given application. G loading in the directionof flight length L3 and G loading on valve assembly 42 compensates forthe increase in the force of spring 58 when it is compressed to preventthe increased force from causing an increased fuel flow past the valve44. While this is not deemed necessary, it can be shown by computationthat the valve structure disclosed will perform its intended function,over a range of fuel flows, when these various design factors areproperly selected. In fact, this structure has 4been built and operatedsuccessfully.

It is apparent from the above description that the invention provides anovel valve structure capable of elimirratingA G loading effects in afuel or other iiuid supply system.

While but one embodiment of the invention has been disclosed anddescribed, other modications thereof are possible within the scope ofthe appended claim.

What we claim as our invention is:

A dynamic load fuel compensator, comprising a housing having an inlet,an outlet, a first passageway therebetween, valve means in said firstpassageway, a source of fuel under constant pressure, a rst conduitcommunicating between said source of fuel and said inlet, a fuelldischarge nozzle, a second conduit communicating the pressure upstreamof said outlet to said discharge nozzle and means operatively associatedwith said valve means, for maintaining the fuel flow therepast constantand for eliminating the effect of dynamic loading on the fuel flowingbetween said source and said discharge nozzle, said means including rstand second chambers formed in said housing, pressure responsive meansxedly secured to said valve means and forming a movable wall rbetweensaid iirst and second chambers, resilient means in said first chamber,an outlet to the atmosphere formed in said iirst chamber and a secondpassageway communicating between said rstfpassageway and said secondchamber in orderthat the pressure differential across said pressureresponsive means may balance the force of said resilientv means portionsof said rst and second conduits, said second passageway and the axis ofsaid valve-being parallel to each other and to the direction in whichthe dynamic loading is applied.

References Citedfby the Examiner UNITED STATES PATENTS 646,428 4/ 1900Hardie 137-505.18 X 2,343,375 3/ 1944 Herman 137-505 .26 X 2,795,106 i6/1957 Martin 158-36 X 2,827,762 3/1958 Towns 60-35.6 X 3,015,210 1/1962 Williamson et al. 60-35.6 X 3,137,128 6/1964 lFrancais et al.60-35.6 3,174,280 3/1965 Ackland et al. 60-3928 FREDERICK KETTERER,Primary Examiner.

